Power converters may be used for converting direct current (DC) voltage to a different DC voltage or an alternating current (AC) voltage. Converter construction may typically make use of power transistors and diodes. The power transistors and diodes may be operated as electronic switches. Certain converter designs may use “hard” switching, which may give rise to switching losses which, for high values of the switching frequency, may cause a reduction in energy conversion efficiency. Hard switching may be characterized by a total commutation voltage drop over the current-carrying switch at a current commutation time. In case of hard switching, the voltage may increase up to the value of the commutation voltage while the current continues flowing, before the voltage drops, that may cause high power loss peaks in the switch. It may therefore be desirable to develop converter topologies and switching methods that enable “soft” switching, which may reduce total switching losses.
In attempts to improve converter efficiency and reduce costs, high-power converters may make use of a technique referred to as multi-level conversion. Multi-level converter design may reduce the occurrence of simultaneously high values of voltage and current, and hence high-power dissipation values, during the switching process. Additionally, multi-level converter topologies may provide multiple output voltage values, which may reduce the size of associated output filters. It may be desirable to develop converter topologies and efficient switching methodologies to improve the cost and/or efficiency of inverters.